The present invention refers to an activator for the absorption of cosmetic compositions, as well as to a series of new compositions for cosmetic use.
The activator, consisting of a specific component, that is, benzyl alcohol, has the function of facilitating the mechanism for the absorption of the other components through the skin and its associated organs.
Several chemical and physical properties and pharmacological activities of benzyl alcohol have been known for a long time, but it has never been thought to connect these with what may be one of its specific uses in cosmetics and dermopharmacy, as is now, however, the object of the present invention.
Benzyl alcohol, C.sub.7 H.sub.8 O, also called phenylcarbinol and .alpha.-hydroxytoluene, corresponds to the following chemical structure: ##STR1##
Its molecular weight, for this formula, is 108.13; the theoretical elementary analysis gives: C 77.75%, H 7.46%, O 14.80%. This is a natural constituent of the essential oils of jasmin, hyacinth, ylang-ylang and of balsams of Peru and Tolu, as well as storax. Commercially it is obtained by synthesis, starting from benzyl chloride, by reflux in the presence of sodium or potassium carbonate, in an anhydrous environment (R. E. Kirk and D. F. Othmer, Editors, Encyclopedia of Chemical Technology, Vol. 2, Interscience Encyclopedia, New York 1948, pp. 483-486). At ordinary temperatures and pressures it is a limpid, colourless, mobile and refracting liquid with a slight, aromatic, pleasing odour, of density (20.degree. C.) 1.04535; melting point--15.19.degree. C.; boiling point 204.7.degree. C. (760 mm of Hg), 80.8.degree. C. (5 mm of Hg). Soluble in about 25 parts of water and in 1.5 parts of 1:1 water--ethanol; miscible with ethanol, ethyl ether, chloroform and many other polar or apolar organic solvents (The Merck Index, Ninth Ed., No. 1138, p. 148, Rahway, N.J., 1976). It is used in the manufacture of perfumes, pharmaceutical and parapharmaceutical products and its esters are used in soaps, in perfumes and in food flavourings (A. K. Doolittle, The Technology of Solvents and Plasticizers, Wiley, N.Y. 1954, p. 672; I. Mellan, Industrial Solvents, Reinhold, N.Y. 1950, p. 86, p. 519).
Its local antiseptic and anaesthetic properties are currently used, and this use is favoured by the fact that its acute toxicity is very low (LD.sub.50 =3100 mg/kg, oral, rat), while toxic effects in subacute or chronic measure have not been recorded, above all because of the fact that it is rapidly oxidised within the organism and eliminated in the form of hippuric acid or benzoyl glycine (H. F. Smyth, Jr., C. P. Carpenter and C. S. Weil, Arch.Ind.Hyg. Occupational Med., 4, 119; 1951). Within 6 hours of the oral ingestion of 1.5 g of benzyl alcohol human subjects eliminate 75-85% of the dose in the urine as hippuric acid (I. Snapper, A. Grunbaum and S. Sturkop, Biochem.Z., 155, 163; 1925; see also: J. A. Stekol, J.Biol. Chem., 128, 199; 1939).